A 0.18 μm CMOS on-chip skin detection scheme based on NPNP-triple-junction structure

In this paper, a 0.18 μm CMOS color processing scheme based on NPNP-triple-junction structure is proposed to achieve real-time skin detection. The need for building complex demosaicing circuitry is completely eliminated, which dramatically reduces the fabrication cost and simplifies the pixel space sampling algorithm. In addition, real-time detection is enabled through the use of logarithmic readout mode and Gilbert normalization cell. The fabricated chip and related measurement results have verified the concept of a compact, low cost, CMOS fully compatible micro-sensor suitable for skin detection.